Documentation/content/world/worldgen/climate-biomes.en.md

title, type, weight

title	type	weight
Climate & Biomes	docs	3

The climate and biome system determines biome distribution across the world based on temperature, humidity, and other factors.

Package: com.hypixel.hytale.server.worldgen.climate

Climate System

The ClimateGenerator creates climate maps:

public class ClimateGenerator {
    // Get temperature at position
    public float getTemperature(int x, int z);

    // Get humidity at position
    public float getHumidity(int x, int z);

    // Get altitude factor
    public float getAltitude(int x, int y, int z);

    // Get climate data
    public ClimateData getClimate(int x, int z);
}

ClimateData

public class ClimateData {
    private float temperature;  // -1.0 (cold) to 1.0 (hot)
    private float humidity;     // 0.0 (dry) to 1.0 (wet)
    private float altitude;     // Normalized height
    private float continentality; // Distance from ocean

    public Biome getBiome();
}

Biome Selection

Biomes are selected based on climate parameters:

public class BiomeSelector {
    private Map<BiomeCondition, Biome> biomeMap;

    public Biome selectBiome(ClimateData climate) {
        for (Map.Entry<BiomeCondition, Biome> entry : biomeMap.entrySet()) {
            if (entry.getKey().matches(climate)) {
                return entry.getValue();
            }
        }
        return defaultBiome;
    }
}

public class BiomeCondition {
    private Range temperatureRange;
    private Range humidityRange;
    private Range altitudeRange;

    public boolean matches(ClimateData climate) {
        return temperatureRange.contains(climate.temperature)
            && humidityRange.contains(climate.humidity)
            && altitudeRange.contains(climate.altitude);
    }
}

Biome Definition

# biomes/forest.yaml
Type: Biome
Id: forest
DisplayName: "Forest"
Climate:
  Temperature: [0.3, 0.7]
  Humidity: [0.4, 0.8]
Terrain:
  SurfaceBlock: grass
  SubsurfaceBlock: dirt
  StoneBlock: stone
Features:
  - Type: Tree
    Density: 0.3
    Variants: [oak, birch]
  - Type: Grass
    Density: 0.8
  - Type: Flower
    Density: 0.1
Mobs:
  - Type: deer
    SpawnWeight: 10
  - Type: rabbit
    SpawnWeight: 20
AmbientSounds:
  - birds
  - wind_leaves

Temperature Zones

public enum TemperatureZone {
    FROZEN(-1.0f, -0.5f),    // Ice, snow
    COLD(-0.5f, 0.0f),       // Taiga, tundra
    TEMPERATE(0.0f, 0.5f),   // Forest, plains
    WARM(0.5f, 0.8f),        // Savanna, jungle
    HOT(0.8f, 1.0f);         // Desert, volcanic

    private float min;
    private float max;
}

Humidity Zones

public enum HumidityZone {
    ARID(0.0f, 0.2f),        // Desert
    DRY(0.2f, 0.4f),         // Savanna, steppe
    MODERATE(0.4f, 0.6f),    // Plains, forest
    HUMID(0.6f, 0.8f),       // Jungle, swamp
    WET(0.8f, 1.0f);         // Rainforest, marsh
}

Biome Blending

Smooth transitions between biomes:

public class BiomeBlender {
    private int blendRadius;

    public BiomeBlendData blend(int x, int z) {
        Map<Biome, Float> weights = new HashMap<>();

        // Sample surrounding biomes
        for (int dx = -blendRadius; dx <= blendRadius; dx++) {
            for (int dz = -blendRadius; dz <= blendRadius; dz++) {
                Biome biome = getBiome(x + dx, z + dz);
                float distance = (float) Math.sqrt(dx * dx + dz * dz);
                float weight = 1.0f / (1.0f + distance);
                weights.merge(biome, weight, Float::sum);
            }
        }

        return new BiomeBlendData(weights);
    }
}

Climate Noise

public class ClimateNoiseGenerator {
    private SimplexNoise temperatureNoise;
    private SimplexNoise humidityNoise;

    public ClimateNoiseGenerator(long seed) {
        temperatureNoise = new SimplexNoise(seed);
        humidityNoise = new SimplexNoise(seed + 1);
    }

    public float getTemperature(int x, int z) {
        // Large scale temperature variation
        float base = temperatureNoise.noise2D(x * 0.001f, z * 0.001f);
        // Small scale variation
        float detail = temperatureNoise.noise2D(x * 0.01f, z * 0.01f) * 0.2f;
        return base + detail;
    }

    public float getHumidity(int x, int z) {
        return humidityNoise.noise2D(x * 0.002f, z * 0.002f);
    }
}

Altitude Effects

public class AltitudeClimateModifier {
    // Temperature decreases with altitude
    public float modifyTemperature(float baseTemp, int altitude) {
        float altitudeFactor = altitude / 256.0f;
        return baseTemp - (altitudeFactor * 0.5f);
    }

    // Humidity varies with altitude
    public float modifyHumidity(float baseHumidity, int altitude) {
        if (altitude < 64) {
            return baseHumidity * 1.2f; // More humid at low altitudes
        } else if (altitude > 128) {
            return baseHumidity * 0.6f; // Drier at high altitudes
        }
        return baseHumidity;
    }
}

Configuration

# worldgen/climate_config.yaml
Climate:
  NoiseScale: 0.001
  TemperatureRange: [-1.0, 1.0]
  HumidityRange: [0.0, 1.0]
  BlendRadius: 8
  AltitudeEffect: true
Biomes:
  - Id: forest
    Temperature: [0.3, 0.7]
    Humidity: [0.4, 0.8]
  - Id: desert
    Temperature: [0.7, 1.0]
    Humidity: [0.0, 0.3]
  - Id: tundra
    Temperature: [-1.0, -0.3]
    Humidity: [0.2, 0.6]

Best Practices

{{< callout type="info" >}} Climate Guidelines:

• Use smooth noise for natural climate transitions
• Consider altitude when determining biomes
• Blend biomes for seamless transitions
• Test biome distribution across large areas {{< /callout >}}